In general, in controlling a vehicle, cognitive information on a vehicle in front, and information corresponding to distance and speed of the front vehicle are frequently used for controlling a distance between cars.
Radar is most commonly used in controlling distance between cars; however, radar not able to accurately determine that the object in front in fact is a vehicle, but may determine the vehicle just by using speed. Therefore, radar may not be able to determine accurately whether what is in front is a low-speed vehicle or a stopped vehicle.
Accordingly, technology for detecting the vehicle based on an image is applied; however, many computations may be required to detect the vehicle from an image, and as a result, accuracy recognizing the vehicle from the image may be degraded when the surroundings are dark, such as at night time or inside a tunnel.
Therefore, although it is possible to detect the front vehicle by combining the radar and image technology, as described above, it may be difficult to identify accurately when the vehicle drives at low-speed at night or when the vehicle is stopped.